Applied WPF 4 in Context (
http://www.apress.com/9781430234708) starts with a simple introduction to WPF and then shows a complete WPF application from sketch to completed code. This APress web site states "This book can be used by a junior developer to learn WPF and understand
how to architect a layered application, and it can also be used by a
senior developer as a reference for developing scalable WPF
applications. " - this summerises the book very effectively as it is indeed an excellent book both for learning WPF and as a reference for development. I recommend it to all Dot Net development teams.